Voice over Internet protocol (VOIP) refers to a set of standards for communicating digitized voice in form of data over an IP-based network, such as the Internet. Current VOIP systems use different communication protocols, such as packet based telecommunication protocol H.323 and session initiation protocol (SIP), to set up calls between one or more communication endpoints. Each endpoint (i.e., end device) may communicate over a different communication protocol, such that one end device may communicate over the H.323 protocol and another end device may communicate over the SIP, for example.
To support communication between end devices that use different VOIP protocols, basic models for interworking the H.323 and SIP protocols have been implemented. Interworking refers to the process of mapping a communication method or message supported in one protocol to a corresponding communication method or message in another protocol. Thus, for example, a call between two end devices can be set up, even if one end device communicates over the H.323 and another end device communicates over the SIP.
A set of standards known as H.450 have been suggested by the International Telecommunications Union (ITU) to support supplementary services for H.323. Supplementary services include call services such as call forward, call transfer, call hold, call wait, call identification, etc. Unfortunately, the current interworking solutions support a few types of call connections and do not provide an interworking solution for supplementary services in a non-H.450 communication framework.
Accordingly, systems and methods are needed that can overcome the aforementioned shortcomings.
Features, elements, and aspects of the invention that are referenced by the same numerals in different figures represent the same, equivalent, or similar features, elements, or aspects, in accordance with one or more embodiments.